The description refers to a printer with an air pressurization system and to a method of building up air pressure in a printing fluid supplier. Printers, such as inkjet printers, with an air pressurization system, for example air pumps, are pressurized to reach a working air pressure. For example, in an inkjet printer the air pumps build up a working air pressure inside a common volume of a plurality of printing fluid suppliers to make the printing fluid flow from the printing fluid suppliers to the print heads. With ongoing use, the air pumps degrade, for example as a result of the fatigue of the material. This degradation leads to problems with the printer. Among these problems are, for example, job cancellation resulting in a waste of paper and printing fluid, functionality reduction, e.g. the continuous printing fluid delivery function, which switches to another printing fluid supplier when the currently used one runs out of printing fluid, could be disabled if it is impossible to recover the working air pressure during a cartridge swap, or the failure of the print heads (starvation failure) if they run out of printing fluid as a consequence of the lack of pressure on the printing fluid suppliers. To avoid these printing problems, some commercially available printers depressurize the system and automatically cancel the job when the pressure decreases below a lower limit. That is, the printer acts automatically in order to protect the components and the user has no other option but to reboot the printer. When these interruptions become more frequent, the user has to replace components. For some commercially available printers this means that the user has to contact support to get the system repaired with the inconveniences associated of having the printer turned off during this time.